The Tory leadership frontrunner was facing three allegations of misconduct in public office and issued a summons to attend Westminster Magistrates’ Court on May 29. Today, at a hearing in London, Lady Justice Rafferty and Mr Justice Supperstone overturned the earlier decision. Addressing Mr Johnson’s barrister, Adrian Darbishire QC, Lady Justice Rafferty said: “We are persuaded, Mr Darbishire, so you succeed, and the relief that we grant is the quashing of the summonses.”

The judge said reasons for the court’s ruling will be given at a later date.

Campaigner Marcus Ball, 29, crowdfunded more than £300,000 through an online campaign to bring the prosecution.

In the run-up to the June 2016 Brexit referendum, Mr Johnson had toured in a red bus emblazoned with the slogan: “We send the EU £350 million a week, let’s fund our NHS instead”.

Mr Darbishire argued that the attempt to prosecute Mr Johnson was “politically motivated and vexatious”.